It has heretofore been suggested that a tamper-indicating band be connected to a closure, the band having flexible portions that are deflected over an annular bead on the container and under the annular bead such that when the closure is unthreaded from the container, the flexible portions cause the band to be severed from the remainder of the closure indicating that the closure has been opened.
In U.S. Pat. Nos. 4,350,844 and 4,613,052, having a common assignee with the present application, there is disclosed and claimed a screw type cap of plastic with a tamper-indicating ring or band that is carried at the lower end of the skirt of the closure with frangible bridges forming the connection. The removal of the closure results in the indicating lower position on the neck and is presented from being returned to its, as applied, position. A container has a finish, below external threads which is formed with an inwardly and downwardly tapering side wall which leads to an abrupt, horizontal ledge such that when an indicating band is severed from a closure, on removal, the band falls below the ledge and cannot be returned. The closure is formed with internal threads in the skirt and at the bottom of the skirt a band or ring of about the same external diameter as the cap is formed with frangible bridges joining the band to the skirt. Within the indicating band, an inwardly extending flexible stop ring is formed integral with the indicating band. A particular finish on the container provides a pair of radial ledges which extend outwardly below the threads on the container neck. These ledges are vertically displaced relative to each other and are joined by an inwardly tapering wall which is adapted to form the surface on which the stop ring will be seated when the closure is applied. The stop ring prevents removal of the closure without the separation of the indicating band from the closure skirt.
In U.S. patent application Ser. No. 820,034, filed Jan. 21, 1986, having a common assignee with the present application, there is disclosed a tamper-indicating package comprising a container having a neck with a threaded finish and a closure which includes a base wall and depending peripheral skirt having threads interengaging the threads of the container, and a tamper-indicating band attached to the skirt by a plurality of circumferentially spaced frangible bridge members. The tamper-indicating band includes a bead for engaging a complementary bead on the container, and a segmented annular flange extending axially upwardly and inwardly from the lower edge of the tamper-indicating band towards the base wall of the closure. The annular flange has its free edge formed with a plurality of segments such that the stiffness of the flange is reduced. In addition, the leading end of each segment is cut to a 30.degree. angle. These two features facilitate the application of the closure to the container.
In U.S. Pat. No. 4,546,892, there is disclosed a plastic tamper-indicating closure which has an annular wall extending upwardly and inwardly and an annular bead or heel along the inner surface of the wall so that when the closure is applied to a container, the annular wall is interposed between the skirt of the closure and the finish of the container and the bead engages the underside of the ring on the finish to hold the closure in position.
In tamper-indicating packages which utilize closures that have flexible portions associated with the tamper-indicating band, when such closures are utilized with glass containers that have a wide range of tolerances, it is sometimes difficult to insure that proper clearance will be provided. In addition, because of the flexibility of the portions, there may be concern that somehow a user might attempt to deflect the portions in order to remove the closure and thereby defeat the purpose.
In the molding of such closures, it is often necessary to use complex molds and, in addition, post molding operations such as reforming in order to make the closure function.
Accordingly, among the objectives of the present invention are to provide tamper-indicating closure and package which will provide a tamper evident feature which is more reliable over a wider range of finish tolerances and which is much more difficult to defeat than certain plastic closures that have plural flexible portions that engage the container and which requires simpler tooling; which does not require post molding operations; wherein the torque required to apply the closure is reduced; and which will accommodate a wide range of tolerances.
In accordance with the invention, a tamper-indicating closure and package comprising a one-piece molded closure of plastic and a container having interengaging means such that when the closure is removed, a tamper-indicating ring becomes separated from the lower end of the closure skirt. The tamper-indicating band is joined to the closure along the weakened frangible line. Circumferentially extending relatively rigid locking members are supported on the inner surface of the closure by generally vertically extending flexible membranes such that when the closure is threaded onto the container, the locking members move radially outwardly as they engage an annular bead on the finish of the container causing the membranes to flex over the bead and bringing the locking members into engagement with the underside of the bead. When the closure is removed from the container, the engagement of the locking members with the underside of the bead causes the membranes to be severed. in one form of closure, the membranes are inclined circumferentially opposite to the direction of rotation of the closure during threading to facilitate the flexing of the membranes.